<template>
	<view>
		<my-search @click="gotoSearch"></my-search>
		
		<view class="scroll-view-container">
			<!-- 左侧的滚动视图区域 -->
			<scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
				<block v-for="(item,i) in cateList" :key="i">
					<view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
				</block>
			</scroll-view>
			<!-- 右侧的滚动视图区域 -->
			<scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
				<view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
					<view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<!-- 三级分类 Item 项 -->
						<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
							<image :src="item3.cat_icon"></image>
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
			  </view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	
	import badgeMix from '@/mixins/tabbar-badge.js'
	
	export default {
		mixins: [badgeMix],
	    data() {
	      return {
	        // 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
	        wh: 0,
			cateList: [],
			active: 0,
			cateLevel2: [],
			scrollTop: 0
	      };
	    },
	    onLoad() {
	      // 获取当前系统的信息
	      const sysInfo = uni.getSystemInfoSync()
	      // 为 wh 窗口可用高度动态赋值
	      this.wh = sysInfo.windowHeight
		  
		  this.getCateList()
	    },
		methods: {
			async getCateList() {
			  const { data: res } = await uni.$http.get('/api/public/v1/categories')
			  if (res.meta.status !== 200) return uni.$showMsg()
			  this.cateList = res.message
			  // 为二级分类赋值
			  this.cateLevel2 = res.message[0].children
			},
			activeChanged(i) {
			  this.active = i
			  // 为二级分类列表重新赋值
			  this.cateLevel2 = this.cateList[i].children
			  
			  this.scrollTop = this.scrollTop === 0 ? 1 :0
			},
			gotGoodList(item3) {
				uni.navigateTo({
					url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
				})
			},
			gotoSearch() {
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		}
	  }
</script>

<style lang="scss">
	.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
  }
  .cate-lv2-title {
  	font-size: 12px;
  	font-weight: bold;
  	text-align: center;
  	padding: 12px 0;
  }
  
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }
</style>
